Jay - ONO generally use their OWN dark fibre backbone. If this is the case - then should be OK.

I've a business contact (supplier) in Madrid who's just moved his business across to ONO - but where he lives the ONO service is not as good. You need to find out how it is where you have the flat/shop etc!. CASE by CASE.

ONO was VERY hot on getting their backbone into business parks and newer developments. But there's not always been a chance to cable ALL streets especially in older sectors.

I've seen businesses die in Madrid CITY moving from one ISP to another - seriously. Why? because despite what they've sold they in fact use somebody else backbone to make the connection. And when it went kaput NOBODY would accept responsibility.